Friday, August 19, 2011

A cricketer can throw a ball to a maximum horizontal distance of 100m. What is the speed at which he throws the ball?

Hello!


The maximum distance is reached when the angle of elevation is 45°. Denote the initial speed in question as and consider the projection of motion on the horizontal and vertical axes.


Along the horizontal axis the speed is constant (the only force is the gravity one and it is vertical). The initial horizontal speed is Therefore the time of a flight is


Along the vertical axes acts the gravity force which gives the acceleration g downwards. The height is



And at the time the height is zero, i.e.



or


or


No comments:

Post a Comment

How does author Elie Wiesel use symbolism to contribute to the meaning of Night?

In his book Night , Elie Wiesel uses symbolism throughout to enhance the text. First of all, the title itself is symbolic. The word "ni...